This invention relates, in general, to wafer probe systems and methods therefor and, more specifically, to a semiconductor wafer front side pressure testing system and method therefor.
As surface micromachining replaces bulk micromachining, it has become more important in semiconductor device manufacture to provide a higher percentage of xe2x80x9cknown good diexe2x80x9d for increasing yield and for reducing costs in final manufacturing. This is important as the final manufacturing stage, including the processing of the wafer into a multitude of individually packaged devices, is one of the most expensive areas in semiconductor production. The packaging and post-package testing costs make it very advantageous to test a semiconductor chip or device prior to the packaging stage, and ideally, each device would be fully functionally tested prior to packaging. The testing step, normally performed during a wafer probe operation, is ideally suited for electrical testing as the probe pads are all accessible on the surface of a wafer held on its backside by a vacuum chuck.
Some devices on a wafer, however, are not purely electronic in nature, but instead are designed to register or measure physical or environmental conditions. These conditions may include, for example, acceleration, temperature, and pressure. Thus, it is also desirable to be able to functionally test these physical effect devices prior to the packaging stage.
Hence a need exists for a method and apparatus capable of testing semiconductor devices in wafer form while they are being exposed to physical conditions such as pressure changes.